Matilda, Lady of the English (1102-1167) was the daughter and dispossessed heir of Henry I of England. When Henry died in 1135 with no male heir, Matilda was in Anjou and the monarchy was usurped by her cousin Stephen who previously pledged to defend her right of succession. There was an extended period of civil war but not until 1139 was Matilda able to command the military power to take the fight to English soil. In 1141 Matilda defeated Stephen in April 1141 at the Battle of Lincoln, where he was taken prisoner and effectively deposed. In common with the Anglo-Saxon custom of female rulers, Matilda called herself Lady of the English rather than queen. Matilda marched to London for her coronation in July but the citizens demanded that she halve their taxes before she was allowed to enter. She refused and civil war was resumed. In November she swapped the imprisoned Stephen for her captured half-brother, and in early 1142 suffered defeat at Oxford where she was forced to flee for her life. Stephen reinstated himself as king.

She was the first female ruler of the Kingdom of England. However, her failure to secure that rule meant that her undisputed period of reign in 1141 was extremely brief. Consequently she is often excluded from lists of English monarchs.